Toward pulping process for enhancing the RS-black liquors as precursor of activated carbons for aqueous adsorbent purposes

Vivian F Lotfy; Zhichao Bao; Xuesong Zhou; Altaf H Basta; Shiyu Fu

doi:10.1038/s41598-023-47447-4

Toward pulping process for enhancing the RS-black liquors as precursor of activated carbons for aqueous adsorbent purposes

Sci Rep. 2023 Nov 16;13(1):20072. doi: 10.1038/s41598-023-47447-4.

Authors

Vivian F Lotfy¹, Zhichao Bao², Xuesong Zhou², Altaf H Basta³, Shiyu Fu⁴

Affiliations

¹ Cellulose and Paper Department, National Research Centre, El Buhouth St., Dokki, 12622, Giza, Egypt.
² State State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China.
³ Cellulose and Paper Department, National Research Centre, El Buhouth St., Dokki, 12622, Giza, Egypt. altaf_halim@yahoo.com.
⁴ State State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China. shyfu@scut.edu.cn.

Abstract

This work deals with providing a green pulping process of rice straw with zero waste discharged, via valorization of its by-product as a promising precursor for production of carbon nanostructures. The carbon nanostructures (BL-CNSs) from rice straw pulping liquors (BLs) are prepared in one step with phosphoric acid activation. The carbon nanostructures (BL-CNSs) from rice straw pulping liquors (BLs) are prepared in one step with phosphoric acid activation. The optimal pulping approach for achieving effective adsorbent (BL-CNSs) of cationic and anionic dyes is recommended from using different BLs precursors resulting from different reagents (alkaline, neutral, and acidic reagents). The carbon precursors are characterized by elemental, thermal (TGA and DTG) and ATR FTIR analyses. While the impact of pulping route on performance of CNSs is evaluated by their adsorption of iodine, cationic dye and anionic dye, as well as ATR-FTIR, textural characterization, and SEM. The data of elemental analysis displayed a high Carbon content ranges from 57.85 to 66.69% suitable for CNSs preparation, while the TGA showed that Sulphur-containing BLs (Kraft, neutral sulfite and acidic sulfite) have higher degradation temperature and activation energies as compared with other BLs. The optimum BL-CNSs adsorbent is prepared from the disposed neutral sulfite black liquor, with the following characteristics: cationic dye adsorption capacity 163.9 mg/g, iodine value 336.9 mg/g and S_BET 310.6 m²/g. While the Kraft-CNSs provided highest anionic adsorption (70.52 mg/g). The studies of equilibrium and kinetic adsorption of dyes showed that the adsorption equilibrium of all investigated BL-CNSs toward MB follow the Langmuir and mainly Freundlich models for BB adoption. Their adsorption kinetics are a good fit with the pseudo-second-order model. The textural characterization and SEM revealed the CNSs exhibit a mixture of mesoporous and microporous structure.

Grants and funding

43068/Science and Technology Development Fund